<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			function box(a){
				for(var i=0;i<a;i++){
					if(a==1){
						return 1;
					}else{
						return(a*box(a-1));
					}
				}
			}
			var index=box(10);
			alert(index);
		</script>
	</body>
</html>
